SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b89ba5c72028f70f692bcfdc80b1998630a68afcf94a3f5e2d42715983ec5edf' 
  AND token = 'P9DSjuMR6uvsGrkieLHbhskAAbFg4O7iuhysYCKl5vc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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