SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9db91e672bb0f112b2a3f787b5916cc1f2faafa49cf888d547c7ded5c350be6f' 
  AND token = '1tGgkHybr6jYekXjPiM79EmfoWrdcYkJllobUcr2/Rc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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