SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fb1f44f50a4d292810b4a8b504c05141bbac4e9772a32962abe7282a73943c1c' 
  AND token = 'z9ygP1tP4qHHTLyhyk3/vtm47Js/E9WJSn41jo8xnqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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