SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09794aae7e5372aeedaa6acc4800e1828322995d54640976495fdb96a9636e18' 
  AND token = 'kvcrw1EWNhzyEoNuCydCtJS01R98NZfsNik4DFjcIHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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