SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e548ba247dba27e87780e49b5ad6d5e9c19b3a834714362898ee056329af741' 
  AND token = '+BrD/ogjBVhwgocWWq9fJgw9807EzJt4HA81u+Qw3JM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}