SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '455c6400614ff807e627deb891fc1f4a31ad9e5036758e3f59c954744a56a8ba' 
  AND token = 'VsYmCZAHRkMiNrxB427/yvK37c6O9htlATn4gSBaqwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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