SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a124b2a083abf927afe29cd2d756216a93e8f2782d8b0ee1bda66b1909353853' 
  AND token = 'dMoj1qRlw2YWHBsn3Qr2PH/0yVnwAmaaus8E29Sx338=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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