SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a38a74ee151297e8e00115060b55fb454748b357091f694ca32fd5b649bd2a36' 
  AND token = 'wzKWggZkYbKF5uQhdP2iXgGJv0pbQ6eCNElI4PlFkRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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