SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30e5212d2add1c51b3073b7ba610675bf51fdf4135866f326b31f9d3375703d5' 
  AND token = 'rrkWKnOjF/VAwR//DqL5FCcOgInHf4I2PqMeeJyCYXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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