SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b77275738b780f11681a9f1735e51c1b681c5ef0aa0e7479782281880da6134' 
  AND token = 'D5uVQPKj6Bt5migTH/DFOyR+r0FSPHjlo3095224xLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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