SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a67b590724fe86eff89556547a0981a897196d65a1d003044341f53016d8448' 
  AND token = 'S76jZsbZnQF2IzengMn47AjuCY2vcFX753Uf0xykRKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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