SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e6060b83f5965f8624ad72f4bba096ec3ab1d5bddfad35cd2782cabe94ec36f' 
  AND token = '+tbRdQnztzoRafdaMn+0wgciaG/8YumwCpMdOflkBxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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