SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b9fa8ab3f748bd36edf674f991c525f396848c6db63f372c7535e9a1aa58232' 
  AND token = 'z/GV3RmZy/aKk5A6YX+r+eni0SIGOEbMBGGTF5bLL9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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