SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70b147f7c681703f73b7bc41279b5fbf35e241daa69eddeacab10d07c09a747c' 
  AND token = 'wT5mTB1w9ACALqrV4BJI3/wGLyWKhvqzp9gRHe++vp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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