SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9177be4df392d059f667b04950e6b19e02d32c1967c9886e3709d68bdc515f4' 
  AND token = 'rIeMAYh0Z/K8YdE8/Jp9VDRO1zZJyoda90tnqXbMtG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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