SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b13eb0d344c68b195fbfb446cb818c599547c81d48dfab56cfe7a762979320a1' 
  AND token = 'S2zD+lo8f/7lxQ591+IEHjZsUnzGvzdAAAoLs06Vgq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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