SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f018b54009e024b5ee67f273ed34022970299201f6e5d12f7bdc3ba87191e24' 
  AND token = 'CMCCrF95a8EPwjO/fTcx57LsWAZqdd6orKQ9TGYGhPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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