SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bdc355d23dccd7cc8f93810e8ded26b3864b26a2ae93d5632049c09af0656e5' 
  AND token = 'tpJurO1KPLbq/5cjKIDu98dPfN5reGCKsPeLOgRl45g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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