SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1c3fafd29771ee54cd355bca16f2cc18076fd58693229da8fa92b63613fde4b' 
  AND token = 'i1ICSdfUFwvPbjQnxgTqU4sikbYFtPy+i9Vwb4ifGCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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