SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb645625e3900bf59d049dcedc4094955e5afa1c703bedf61d6ab9123660fa77' 
  AND token = 'CsEFXxhpRzvANRnYz+cr+v7HeyLjY6izBgGqT/OUnPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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