SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d0535790d39907e88608c299bd1a83f243cd74fdb1898fc40ae9aa9a5315830' 
  AND token = 'VBjyY7qb503JEb3kinwueXBTD8MBBLXOknxOMXr09Pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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