SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e18e456e02dbf9bcd8d6be0421dac7f2258a8849af74ded2652c77cd6ce0cf7' 
  AND token = 'ulv5vxO9LgrHOeixljYYHH8uXfL7CVsGEddp1LH3tXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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