SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c84eb13dc3e6b8927774c33910918c02a07dbe6846746132b1bdd7b9d1862908' 
  AND token = '9VYxGIPz1vKqcykcKDDC0maRJ7OsW9zO2tEEYhS6A2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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