SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '320b542e3a67ecdb0abb1b01abc9c959793fc24709cd552d6faef33492d9822b' 
  AND token = 'OQCjP5FhuEGzAvniP+cKctpYuojXgQdUxWpoVQ/XZHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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