SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f745d35d14e964aa400a62e4a435bf260bb1d223c723ee79c0984062060f1d82' 
  AND token = 'KkaJuLTQmT5wMPCV7W4svbdz8n39E7jItZpInADyUpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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