SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbfabec39b258c1ae994fd590a0a2f2a7d8b5727ba665b1ef5cc110832068299' 
  AND token = 'y/SZavEFSF5PMXuhG9aPlO4S+R61lSh2VtVEAT/IHDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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