SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8984138551acfb15caafc7bf74780f4305d14ffa9c54365dfce7eab9f2446b0b' 
  AND token = '8dhmYboB55Y8PAoZ9+izGYKG5clbKwiuxOxdSTLPY6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}