SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97e5f26f1adf9363a612e28b95c1eff122e861e018db9024875c42e3814ffb1a' 
  AND token = 'zj9dOPUhp7JrxGPGxV5QNq+tIDlHjfNWLouVy4FWhd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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