SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c50e165e8f3f3a784119c1882cfeab2129142edb3a141206d0b80046eb7cf97e' 
  AND token = 'uTGSbFcG2BAu3NXwHXE9jeMfHe5gCTU5QYX2Jop5K84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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