SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f528dc13352580813c95bf93dd83387bfd8fc2a7483cf24bc65d5dd06aca970b' 
  AND token = 'RcmaxfkoydVFmTCM5kBG5fpIrMZ3hGT/dtwm9KvxDTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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