SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63437a3f94510218760727a03f29805e202010156e5dc3b47d1d9d11e890b45e' 
  AND token = 'bsmOVn1aT4XKQr5M53+lP95mjnugvwZBLK/KQnLDows=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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