SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'afe2a67092fc4279ec1aea7bd587015648197901b1104379d8c22fdfaa4f80eb' 
  AND token = '5wMkZO+wyLNCC73RGnBvlO3DUEwbABRflyoq2B+yP4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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