SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd62a3691a6ed393c1eb7d0f93ec4646ebf8cc23604e29af38b5988269110e68f' 
  AND token = '7RqYPKicPXLw/TAqiNp2FDWjK+9dFANvxhGVMPifdbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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