SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24eca24a42fd3ee25aa36529a78a848e0ee60df3af9ce60077b98e963ca79469' 
  AND token = 'ZklOBXTbmLVikfAOFPD/uRZEjjFosCIkL+UksAstBbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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