SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae7441d0de4a4b685f90c28a936736c2a120374485eab3d4b58e9635daa576ed' 
  AND token = 'naIDdR92w87yuskIITBT2TOplOmSCz+5L69X+Iaj/gA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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