SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '431905d59c8122878c0441673e23b4a892a103cb7f14e636bba18b255bc2032c' 
  AND token = 'OKql7N8UH0KTHGYVvtXI7S01E5UZVtfsH2JFDoCiYgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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