SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b83ac9d39ea1a591418c24ae6c1f359a1548241e56c8ff3b51e8af925d6c7d6' 
  AND token = '2I5a//McNj4G3V7RDdK3PZi7gyld69mnZJrTIDshq88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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