SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38f52bf1fdecab851b846427fd5597ec4f4bcf75beb68330ef7a5f264c8d77df' 
  AND token = 'CzYCYuG8rj2woweo6KcRfn/D8WTQxwatf6addtMwYXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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