SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b69a1172a04ed30498fc34f811f173eecf8d64b4eb7a02a3ac7ad375eb3c027' 
  AND token = 'XR4hiIslXEPOE87MrbV6+PYROmUUJ+eFjrADTpKC5Lo=' 
  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"
    }
  }
}