SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '78b8599f4ba6c751deeb8547d2b029c238002061cdaa9b84e45fb4f3f31f6a11' 
  AND token = 'MijeUaDH8bClydJIWJOpBK0DD4uXm0LX4t/iCVkPCtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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