SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8604aa7c5f5799424a5a0294032985f38467a6b2c1bd01d16ebdc799ba4613a' 
  AND token = 'uvAzJz0FG35gx2wrWm97+hAUxonJYlaLUGXMhqI+nLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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