SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eeb77596239ebc8145420e6d591282a5114f7a513ce5eaf29f80368370b3e9ee' 
  AND token = 'slMB64WwTfVDvL0/SSCcDnRY0g8iVdh5iaHC+X2mJ/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}