SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '104b23b03754e3a4eb8875cb6491c0c444549c0c8708693693be08a00d5c5f4e' 
  AND token = 'A0aiZAYDpSGA5QxhvJnnnyLAjJrrFFqiqVZyC0sO5jM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00081

JSON explain

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