SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf17a4f6c94187d418784431f1df353685b2294e29a3f332d11070a863370ea4' 
  AND token = 'OHrT2YIzyolSIAEvNEUn3HFpNSIUvlcfN7Srawg2uEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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