SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4b37a70aa11c201f1e25f6c3ec8a6b110e268f443785c71e228104f197888b7c' 
  AND token = '4ItL9KCXSPhc1qsxYGH4lShBd5ZbbJSDuGN39/BBlEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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