SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2187e0d35fbfa3221a1877f5d49dab908f207429afea171fcd7e8e6f17062c1e' 
  AND token = 'o9L9GkKDXWXfz33LtRGU45RlYiDmJP8CI11uPcVoQeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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