SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd550cd9f6d9763cea2b0b1c0812aaf840949675df26ba06e36f623036ac6d462' 
  AND token = '8BjsGrqFo/I//72nv2nbGNFxIcdAhGYdZWbxaI2BLvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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