SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd85d1ca325e88a526f84f2d3aa308658f757adf745aafdd34ce5f2be819590d5' 
  AND token = 'NCPO/Lp9vuzi4Nb4qLPwvMz2Vf4Wpd0inSHNHdtLmwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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