SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1555f20f4661a36de624ee0dc379cc52e7f1bcf5cf43fc3d67667eebec79c6ab' 
  AND token = 'mdTU4TQCxAWMITGubLwrhVntbW6Ej7+BCklXvR68HcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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