SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dc4398127a348a38607516eeee03d68515c3c1418b3eacae16521d33768ca358' 
  AND token = 'ia2YCSRtZ7e8ev8oaEKZf7RDUcJjaxK+V11/THCNTE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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