SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eadfce60c463247b830769bf2f1cd06a7fb9b3c090c7817c1918716e7300ec30' 
  AND token = 'sx2jIfQXPOCP1arHSrXe3Cp7pCDVFxTv4uORvSOP7KE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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