SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '194d3fab79b9bfd6e6099aac753139b2798840b9b50f100457288c29893bf702' 
  AND token = 'FeNW0qJeI2JHLxPBtxwSVWrh5L7wp4W6quA0AObjdm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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