SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2509612489f0f034931f254e074d7c35cf8ddcacecb81b2d9f5e807fdc33f7a6' 
  AND token = 'Dfna4O4zvwF8+HYpBsCSzLYQ8ClrfJuEwqGffYYxhv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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