SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f257cd467ef806eea4a4c9607478597d7bf9dda293a77763c51f6a02787bf99' 
  AND token = 'hlzE1Wgx5OqwpaPG1YKJWBfn2i9UTl/Mz14dWDPLijU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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