SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '611054309e2a630d167d2b9719ce0c4ac428dc89aedbdc42abeba3458c7e6a47' 
  AND token = '5JccpO/acqoxitvMcXYX6BIHP07yAetepJKIZvBnhb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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