SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd84b5fe568ffb0e632f5704fdadffcadd73f7c15c6dac2b05d580093cc4d63e0' 
  AND token = 'kVA3+ypz9LiEiWhzVKk269Zf2nzpNWSgNDyntxIxCv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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