SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38c5aa34b94a05f53c9e810baca29b26785dd39291ba2078cb00dea8331cf989' 
  AND token = 'fNDZaZjlB7YurjneyWSpuvbG/wMnGRPiXN+cJDnz6i0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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