SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '792d434bad91f9f81f906a2bbe30f908fc2cd8f24cb0ffd53a5d97e7e11dcdec' 
  AND token = '1mR3qT4Fn++NzGvCvszRLFfz01JiGEhhFe1Rw2gKF8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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