SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5c6a4f30a7a7b2fa8dee7eab0701df3a027393c161e5f6550316be5179aed7b' 
  AND token = '/3g6mngisQ/n78Z0IDHxYUv2E2p2tq9r6xMmCQNeYK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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