SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb38b688c5a3b444978fb3cde31a01907a0cbed0d622d0fd3ea035c6fc990e26' 
  AND token = 'FvpHhQIEgFH24A49IDRhY/Qu+EbZ6py/dxDI/McElbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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