SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a791099e5191d568674d11804f52a3aeaa871f446621a28e1ebe53a24d54ecd' 
  AND token = 'ZIiraVX2Y3+DGqm0MFhSjwZwOi/bgVfUKg5JdB1kQEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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